Carousels for processing containers are known and are widely used which comprise a plurality of pans for supporting respective containers to be processed, which are positioned at the peripheral region of the carousel and to which the containers are supplied.
The carousel can be associated with various different types of stations for processing the containers in order to carry out, for example, the filling of the containers, the stoppering or the labeling.
In some applications it is necessary to detect the orientation of the container arranged on the pan in order to be able to carry out the operations required at a preset angular portion of the container.
In the majority of cases, the carousels are provided with devices for the detection of the orientation of the containers which comprise, for each pan, a respective sensor designed to detect, during the rotation of the container on the respective pan, a distinctive indicator constituted for example by a ridge, a notch, a so-called “spot”, etc.
Once the sensor has detected the distinctive indicator, a data processing device connected therewith acquires the signal and associates it with the angular position of the pan at that moment.
Typically each sensor is connected to the carousel by way of a supporting bracket so as to follow the respective container during the rotation of the carousel.
Such solution, although widely used, suffers a number of drawbacks, which in particular are determined by the need to use an extremely high number of sensors and supporting brackets.
This results in the need, in the event of a change of format, to carry out an extremely high number of adjustments on the sensors.
Furthermore, the sensors must often be mobile with respect to the container in order to not impede the processing operations (such as for example the labeling).
Likewise, solutions are known in which the carousel is associated with one or more sensors which are designed to follow, for a certain angular portion, a respective container in order to detect its orientation in order to then bring it into the initial position so as to be able to detect the orientation of a further container arranged upstream in the direction of advancement of the carousel.
A solution of this type is described and illustrated in French patent application no. 2012430 in the name of Firma Otto Sick Metallwarenfabrik.
In such solution the carousel supports rotatably, about its own main rotation axis, a bracket for supporting a sensor, which extends externally to the carousel.
Along the peripheral region of the carousel are advancement elements designed to entrain the bracket in rotation from an initial position for a preset angular portion that is adapted to allow the detection of the orientation of the container.
At the end of the angular portion, the bracket “disengages” from the advancement element and, thanks to the action of a return spring and a stroke limit, it is brought back to the initial position at which it “engages” another advancement element.
Such solution, while conceptually valid, suffers considerable drawbacks in technical and implementation terms.
In fact, as the rotation speed increases, it is extremely problematic to ensure the precision and reliability of the step of engaging the bracket with the advancement elements.
Furthermore, repositioning the bracket by way of the return spring and the mechanical holdback is also problematic from the point of view of precision.
EP 0635452 discloses a carousel provided with an apparatus for the application of sealing capsules on wine bottles, such carousel being provided with optical readers for detecting the orientation of the capsules.
In this case the optical readers are entrained, thanks to the action of a motor with a shaft arranged coaxially to the axis of the carousel, in an alternating back-and-forth motion along a preset angular portion so that, in the outward portion, the angular speed of the optical readers corresponds to that of the container to be monitored.
Lastly, a solution has recently been proposed, disclosed in WO2012/090093, relating to a detection device for containers in motion on a carousel conveyor, which comprises a supporting structure and at least one detection sensor which is connected to the supporting structure and can move with respect thereto.
Such detection device further comprises means of synchronization of the sensor with respect to the container, in order to move it so that the sensor follows the container along at least a part of the advancement path from an initial angular position to a final angular position.
Specifically, the synchronization means comprise a guide, fixed to the supporting structure, and a movable structure mounted slideably on the guide and comprising a closed annular transmission element on which at least one sensor is connected.
In particular, the sensor is fixed to the movable structure in order to move at least from the initial position to the final position.
Such solution suffers the drawback of needing specific means for synchronizing the movement of the sensors with that of the container during the movement of the supporting bracket along the advancement path from the initial angular position to the final angular position.